ASM809, ASM810
Alliance Semiconductor
2575 Augustine Drive . Santa Clara, CA 95054 . Tel: 408.855.4900 . Fax: 408.855.4999 . www.alsc.com
Notice: The information in this document is subject to change without notice
October 2003
rev 1.0 3 Pin Microcontroller Power Supply Supervisor
General Description
The ASM809/ASM810 are cost effective 3.0V, 3.3V and 5.0V
power supply supervisor circuits optimized for low-power
microprocessor (µP), microcontroller (µC) and digital systems.
They provide a reset output during power-up, power-down and
brown-out conditions. They provide excellent reliability by
eliminating external components and adjustments. The
ASM809/810 are improved drop-in replacements for the Maxim
MAX809/810 and feature 60% lower supply current.
A reset signal is issued if the power supply voltage drops below
a preset reset threshold and is asserted for at least 140ms after
the supply has risen above the reset threshold. The ASM809
has an active-low RESET output that is guaranteed to be in the
correct logic state for VCC down to 1.1V. The ASM810 has an
active-high RESET output. The reset comparator is designed to
ignore fast transients on VCC.
Low supply current makes the ASM809/ASM810 ideal for use
in portable and battery operated equipment. The
ASM809/ASM810 are available in a compact, industry standard
3-pin SOT23 package.
Six voltage thresholds are available to support 3V to 5V
systems:
Features:
• Monitor 5V, 3.3V and 3V supplies
• 140ms min. reset pulse width
• Active-low reset valid with 1.1V supply (ASM809)
• Small 3-pin SOT-23 package
• No external components
• Specified over full temperature range - -40°C to 105°C
RESET THRESHOLD
Suffix Voltage
L4.63
M4.38
J4.00
T3.08
S2.93
R2.63
Applications
• Embedded controllers
• Portable/Battery operated systems
• Intelligent instruments
• Wireless communication systems
• PDAs and handheld equipment
• Computers
Typical Operating Circuit
V
CC
V
CC
V
CC
µP
RESET
Input
RESET
(RESET)
GND
GND
(RESET)
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Notice: The information in this document is subject to change without notice
3 Pin Microcontroller Power Supply Supervisor
ASM809, ASM810
October 2003
rev 1.0
Pin Diagram Block Diagram
Pin Description
Pin # Pin
Name Function
ASM809 ASM810
1 - GND Ground.
2 - RESET RESET is asserted LOW if VCC falls below VTH and remains LOW for TRST after VCC exceeds the
threshold.
- 2 RESET RESET is asserted HIGH if VCC falls below VTH and remains HIGH for TRST after VCC exceeds the
threshold.
3-
VCC Power supply input voltage (3.0V, 3.3V, 5.0V).
Detailed Description
A proper reset input enables a microprocessor /
microcontroller to start in a known state. ASM809/810 assert
reset to prevent code execution errors during power-up,
power-down and brown-out conditions.
Reset Timing
The reset signal is asserted- LOW for the ASM809 and HIGH
for the ASM810- when the VCC supply voltage falls below the
threshold trip voltage and remains asserted for 140ms
minimum after the VCC has risen above the threshold.
1
2
3
SOT23
ASM809
(ASM810)
GND
RESET
V
CC
(RESET)
ASM809
ASM810
RESET
RESET
0V
5V
0V
5V
0V
5V
V
CC
V
TH
T
RST
Figure 1: Reset TIming Diagram
+
-RESET Generator
-
+
VCC RESET
(RESET)
GND
ASM809
(ASM810)
4.38V
4.00V
3.08V
2.93V
2.63V
4.63V
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Notice: The information in this document is subject to change without notice
3 Pin Microcontroller Power Supply Supervisor
ASM809, ASM810
October 2003
rev 1.0
Application Information
Negative VCC Transients
The ASM809/810 protect µPs from brownouts and low VCC.
Short duration transients of 100mV amplitude and 20µs or
less duration typically do not cause a false RESET.
Valid Reset with VCC under 1.1V
When VCC is under 1.1V, to ensure logic inputs connected to
the ASM809 RESET pin are in a known state, a 100kΩ pull-
down resistor is needed at RESET . The value of the resistor
is not critical. A 100kΩ pull-up resistor to VCC at RESET is
needed with the ASM810.
Bidirectional Reset Pin Interfacing
The ASM809/810 can interface with µP / µC bi-directional
reset pins by connecting a 4.7kΩ resistor in series with the
ASM809/810 reset output and the µP/µC bi-directional reset
pin.
V
CC
Power Supply
ASM809
RESET
GND 100k
Ω
V
CC
Power Supply
ASM810
RESET
GND
100k
Ω
Power supply
BUF Buffered
RESET
V
CC
ASM809
GND GND
RESET RESET
Input
µC or µP
4.7k
Ω
Bi-directional I/O Pin
Figure 2: RESET valid with VCC under 1.1V
Figure 3: RESET valid with VCC under 1.1V
Figure 4: Bidirectional Reset Pin Interfacing
ASM809, ASM810
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Notice: The information in this document is subject to change without notice
3 Pin Microcontroller Power Supply Supervisor
October 2003
rev 1.0
Absolute Maximum Ratings Table 1:
Absolute Maximum Ratings Table 2:
Parameter Min Max Units
Pin Terminal Voltage With Respect To Ground
VCC -0.3 6.0 V
RESET, RESET -0.3 VCC + 0.3 V
Input current at VCC 20 mA
Output current: RESET, RESET 20 mA
Rate of Rise at VCC 100 V/µs
Note: These are stress ratings only and the functional operation is not implied. Exposure
to absolute maximum ratings for prolonged time periods may affect device reliability.
Parameter Min Max Units
Power Dissipation (TA = 70°C) 320 uW
Operating temperature range -40 105 °C
Storage temperature range -65 160 °C
Lead temperature (Soldering, 10 sec) 300 °C
Note: These are stress ratings only and the functional operation is not implied. Exposure to absolute
maximum ratings for prolonged time periods may affect device reliability.
ASM809, ASM810
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Notice: The information in this document is subject to change without notice
3 Pin Microcontroller Power Supply Supervisor
October 2003
rev 1.0
Electrical Characteristics:
Unless otherwise noted, VCC is over the full voltage range, TA = -40°C to 105°C.
Typical values at TA = 25°C, VCC = 5V for L/M/J devices, VCC = 3.3V for T/S devices and VCC = 3V for R devices.
Symbol Parameter Conditions Min Typ Max Unit
VCC
Input Voltage
Range
TA = 0°C to 70°C
TA = -40°C to 105°C
1.1
1.2
5.5
5.5
V
V
ICC Supply Current
TA= -40°C to 85°C
TA = -40°C to 85°C
TA = 85°C to
105°C
TA = 85°C to
105°C
VCC < 5.5V, L/M/J
VCC < 3.6V, R/S/T
VCC < 5.5V, L/M/J
VCC < 3.6V, R/S/T
9
6
15
10
25
20
µA
VTH Reset Threshold
L devices
TA = 25°C
TA = -40°C to 85°C
TA = 85°C to 105°C
4.56
4.50
4.40
4.63
4.70
4.75
4.86
V
M devices
TA = 25°C
TA = -40°C to 85°C
TA = 85°C to 105°C
4.31
4.25
4.16
4.38
4.45
4.50
4.56
J devices
TA = 25°C
TA = -40°C to 85°C
TA = 85°C to 105°C
3.93
3.89
3.80
4.00
4.06
4.10
4.20
T devices
TA = 25°C
TA = -40°C to 85°C
TA = 85°C to 105°C
3.04
3.00
2.92
3.08
3.11
3.15
3.23
S devices
TA = 25°C
TA = -40°C to 85°C
TA = 85°C to 105°C
2.89
2.85
2.78
2.93
2.96
3.00
3.08
R devices
TA = 25°C
TA = -40°C to 85°C
TA = 85°C to 105°C
2.59
2.55
2.50
2.63
2.66
2.70
2.76
Reset Threshold
Stability 30 ppm/°C
VCC to Reset
Delay VCC = VTH to VTH-100mV 20 µs
Notes:
1. Production testing done at TA = 25°C. Over-temperature specifications guaranteed by design only.
2. RESET output is active LOW for the ASM809 and RESET output is active HIGH for the ASM810.
ASM809, ASM810
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Notice: The information in this document is subject to change without notice
3 Pin Microcontroller Power Supply Supervisor
October 2003
rev 1.0
Reset Active
Timeout Period
TA = -40°C to 85°C 140
100 240
560
840 ms
TA = 85°C to 105°C
VOL
Low RESET
Output Voltage
(ASM809)
VCC= VTH min., ISINK = 1.2mA, ASM809R/S/T 0.3
0.4
0.3
V
VCC= VTH min., ISINK = 3.2mA, ASM809L/M/J
VCC > 1.1V, ISINK = 50µA
VOH
High RESET
Output Voltage
(ASM809)
VCC > VTH max., ISOURCE = 500µA,
ASM809R/S/T
0.8VCC
VCC - 1.5
V
VCC > VTH max., ISOURCE = 800µA,
ASM809L/M/J
VOL
Low RESET
Output Voltage
(ASM810)
VCC= VTH max., ISINK = 1.2mA, ASM810R/S/T 0.3 V
VCC= VTH max., ISINK = 3.2mA, ASM810L/M/J 0.4 V
VOH
High RESET
Output Voltage
(ASM810)
1.8V < VCC < VTH min., ISOURCE = 150µA 0.8VCC V
TRST
Active Reset
Timeout Period VCC > VTH 140 240 msec
Symbol Parameter Conditions Min Typ Max Unit
Notes:
1. Production testing done at TA = 25°C. Over-temperature specifications guaranteed by design only.
2. RESET output is active LOW for the ASM809 and RESET output is active HIGH for the ASM810.
ASM809, ASM810
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Notice: The information in this document is subject to change without notice
3 Pin Microcontroller Power Supply Supervisor
October 2003
rev 1.0
Typical Operating Characteristics
Unless otherwise noted, VCC is over the full voltage range, TA = -40°C to 105°C. Typical values at TA = 25°C, VCC = 5V for L/M/J devices, VCC = 3.3V
for T/S devices and VCC = 3V for R devices.
Normalized Reset Threshold Vs Temperature
Power-up Reset Timeout Vs Temperature
0
2
4
6
8
10
-40 -20 0 20 40 60 85 105 125
Temperature (°C)
Supply Current (mA)
A
SM809T
A
SM809
R
Supply Current Vs Temperature
0.92
0.94
0.96
0.98
1
1.02
1.04
-40 -20 0 20 40 60 85 105 125
Temperature (°C)
Normalized Threshold (V)
A
SM809
R
A
SM809T
0
50
100
150
200
250
300
350
-40 -20 0 20 40 60 85 105 125
Temperature (°C)
Power-up Reset Timeout (ms)
A
SM809
R
A
SM809
T
ASM809, ASM810
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Notice: The information in this document is subject to change without notice
3 Pin Microcontroller Power Supply Supervisor
October 2003
rev 1.0
Package Dimensions
Inches Millimeters
Min Max Min Max
Plastic SOT-23 (3-Pin)
A 0.031 0.050 0.80 1.27
A1 0.004 0.010 0.10 0.25
B 0.015 0.020 0.37 0.51
C 0.003 0.007 0.085 0.18
D 0.110 0.120 2.80 3.04
E 0.047 0.055 1.20 1.40
e 0.035 0.040 0.89 1.03
e1 0.070 0.080 1.78 2.05
H 0.083 0.103
9
2.10 2.64
L 0.027 REF 0.069 REF
S 0.018 0.024 0.45 0.60
B
EH
Se
D
A
A1 e1 C
L
a
ASM809, ASM810
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Notice: The information in this document is subject to change without notice
3 Pin Microcontroller Power Supply Supervisor
October 2003
rev 1.0
Ordering Information:
Related Products:
Part Number 1Reset Threshold (V) Temperature Range Pin-Package Package Marking
(XX Lot Code)
ASM809 ACTIVE LOW RESET
ASM809LEUR-T 4.63 -40°C to +105°C 3-SOT23 SAXX
ASM809MEUR-T 4.38 -40°C to +105°C 3-SOT23 SBXX
ASM809JEUR-T 4.00 -40°C to +105°C 3-SOT23 SCXX
ASM809TEUR-T 3.08 -40°C to +105°C 3-SOT23 SDXX
ASM809SEUR-T 2.93 -40°C to +105°C 3-SOT23 SEXX
ASM809REUR-T 2.63 -40°C to +105°C 3-SOT23 SFXX
ASM810 ACTIVE HIGH RESET
ASM810LEUR-T 4.63 -40°C to +105°C 3-SOT23 SGXX
ASM810MEUR-T 4.38 -40°C to +105°C 3-SOT23 SHXX
ASM810JEUR-T 4.00 -40°C to +105°C 3-SOT23 SIXX
ASM810TEUR-T 3.08 -40°C to +105°C 3-SOT23 SJXX
ASM810SEUR-T 2.93 -40°C to +105°C 3-SOT23 SKXX
ASM810REUR-T 2.63 -40°C to +105°C 3-SOT23 SLXX
Notes:
1. Tape and Reel packaging is indicated by the -T designation.
ASM809 ASM810 ASM811 ASM812
Max Supply Current 15µA 15µA 15µA 15µA
Package Pins 3344
Manual RESET input
Package Type SOT-23 SOT-23 SOT-143 SOT-143
Active-HIGH RESET Output
Active-LOW RESET Output
Alliance Semiconductor Corporation
2575, Augustine Drive,
Santa Clara, CA 95054
Tel: 408 - 855 - 4900
Fax: 408 - 855 - 4999
www.alsc.com
Copyright © Alliance Semiconductor
All Rights Reserved
Preliminary Information
Part Number: ASM809, ASM810
Document Version: v 1.0
© Copyright 2003 Alliance Semiconductor Corporation. All rights reserved. Our three-point logo, our name and Intelliwatt are trademarks or
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ASM809, ASM810
